The present study deals with the thermal conduction of newsprint during the calendering process, a process for surface conditioning of the paper. A comparison is made of the thermal conductivity as determined by the hot plate method with the results from measurements made in real time by temperature gradient calendering, where large temperature gradients are imposed on the paper involving sorptive effects in the moisture content. The results from the latter indicate that the apparent thermal diffusivity of the paper is dependent on temperature of the roller and on the Jacob number, the ratio of the heat of desorption to the heat capacity. The thermal diffusivity decreases with increasing temperature and with increasing Jacob number. This is assumed to be attributed to heat loss from the paper surface to the environment.